The present invention generally relates to a process and arrangement for the adaptive control of a controlled element such as, for example, an internal combustion engine and/or a drive component of a motor vehicle, and more particularly, to such a process and arrangement wherein a characteristic map, storing correction values for selected operating points of the controlled component, is quickly adapted in response to the operation of the controlled component.
German Published Unexamined Patent Application No. 3,436,190 discloses the adaptive control of an automatically shifting speed-change gear as a drive component of a motor vehicle. In this arrangement, a shift time of a gear shift associated with a change in the gear transmission is regarded as a non-steady operating state and is used as a critical time interval for a set value/actual value comparison. The working pressure or shifting pressure, which is used for impingement of shift final control elements actuating friction elements (clutches, brakes) involved in the shift, is considered as one of the decisive factors for determining the duration of the shift time. This shifting pressure is influenced by correction values according to deviations which occur between the set value and actual value of the shift. In the case of this process, the actual value for the shifting pressure is obtained by averaging measured values from a multiplicity of shifts. Since shifts, in most cases, rarely occur at the same operating points, the period of time up to the final adaption of the characteristic map or graph or diagram stored in a memory for determining the correction values is relatively great.
For the same reasons, this disadvantage is shared in a further process disclosed by German Patent Specification No. 3,424,532 for the control of a driving engine having a controlled exhaust catalytic converter, in which a .lambda. probe is positioned both ahead of and behind an air exhaust catalytic converter for optimization c of an air-fuel ratio (.lambda.) in a non-steady state and for detecting the existence of an undesired air-fuel ratio. The detected, undesired air-fuel ratio is correspondingly corrected by means of the .lambda. probe arranged ahead of the exhaust catalytic converter. In the case of this process, correction values for the .lambda. control and the time interval after which the .lambda. probe down stream from the exhaust catalytic converter again indicates a correct air-fuel ratio are only stored for certain, predetermined engine operating states in the non-steady range. Only upon renewed existence of the same engine operating state is recourse made to the stored correction values, the correction values being varied in the direction of the correct .lambda. value. The time interval then obtained is compared with the stored time interval, a time reduction leading to storage of the new correction values and of the new time interval. By repetition of these operations, but only upon recurrence of the same engine operating state, the correction values are iteratively corrected until the time interval reaches a minimum. Here too, the period of time until reaching the minimum value of the critical time interval is thus relatively great.
In the case of a process of a different generic type without adaptive correction intervention for the control of abnormal combustion, i.e. knocking, of an internal-combustion engine as disclosed by German Patent Specification No. 3,049,980, a special measured variable converter is used, which is able to register a parameter dependent on the combustion, for example the pressure and/or temperature conditions prevailing in the internal-combustion engine, and to generate an output signal corresponding to such a parameter value, in order to act on at least one mechanism controlling the combustion in the internal-combustion engine. In the case of this process, the output signal of the measured variable converter is compared with a reference signal, which has a signal value proportional to the engine speed and represents a parameter value with optimal combustion in the internal-combustion engine. According to the deviation between the measured and optimal signal, a deviation signal is generated, which influences the intake pressure of the internal-combustion engine in such a way that the intake pressure is reduced whenever the parameter value registered by the measured variable converter represents conditions with abnormally high pressure and/or abnormally high temperature during the combustion in the internal-combustion engine.
Accordingly, an object of the present invention is to provide an improved process and arrangement for adaptive control of an internal-combustion engine and/or another drive component of a motor vehicle in such a way that a faster ultimate adaptation of a characteristic map or diagram for indicating correction values for selected predetermined engine operating points is achieved, i.e. a respective change in correction values quickly moves to zero after a small number of non-steady operating states.
In the case of the process according to preferred embodiments of the present invention, if appropriate, a correction of the characteristic map takes place after each non-steady operating state irrespective of whether the latter occurred at a selected operating point or at a non-selected operating point, so that the critical period of time is reduced to a small amount, namely to an occurrence of relatively few non-steady operating states.
In the case of the process according to preferred embodiments of the present invention, a type of local flexible network effect in adaptation of the characteristic map is achieved both by entry of a new correction value and by entry of a new transferred correction value, in each case, at the point of a selected operating point of the internal-combustion engine because the new correction value in each case also forms the basis for determining set value and correction value for non-steady operating states occurring at a neighboring vicinity of the associated selected operating point. This has an effect of reducing the number of non-steady operating states necessary for the ultimate adaptation of the characteristic map for the correction values.
One particular advantage of the present invention is that the accuracy, with regard to the correction value formation, is increased in particular.
In the case of the process according to one embodiment of the invention, a damping in the adaptation step of the respectively following non-steady operating state is achieved in an advantageous way.
The process according to the invention can be adapted individually in an advantageous way, in each case, to one or more phases of the respective non-steady operating state, in which there occur, to varying degrees, fluctuations from operating parameters which can have an effect on the time interval.
An advantageous arrangement for carrying out the process according to the invention is also proposed, in which in one embodiment the technical outlay can be kept particularly small, above all with regard to the electronic memory capacities.
In the case of the proposed arrangement for carrying out the process according to the invention, the configuration of the control for a non-steady operating state occurring at a non-selected operating point can be implemented in an advantageous way for the case where the set value/actual value comparison does not produce inadmissible deviations so that a correction of the characteristic map concerned is not to be performed.
In further development of the proposed arrangement for carrying out the process according to the invention, the configuration for control for a non-steady operating state occurring at a non-selected operating point can be provided in an advantageous way for the case where the set value/actual value comparison produces deviations exceeding an admissible extent, so that the characteristic map concerned is corrected.
In the case of the proposed arrangement for carrying out the process according to the invention, the configuration for control for a non-steady operating state occurring at a selected operating point can be implemented in an advantageous way, this configuration also making corrections of the characteristic map concerned possible, if appropriate.
The proposed arrangement for carrying out the process according to the invention can be used universally, i.e. independently of whether the control of the internal-combustion engine or of another drive component of the motor vehicle is concerned.
In the case of the proposed arrangement for carrying out the process according to the invention, a configuration has proved advantageous if the control of the speed-change gear as drive component of the motor vehicle is concerned.
Thus, in the case of the proposed arrangement for carrying out the process according to the invention, the change in the travelling speed is taken into account in a shift producing a non-steady operating state with regard to the gear transmission and a precise operating point in the part-load range is determined for the shift, which is not readily possible by a measurement of the engine speed with a hydrodynamic starting converter connected ahead of the speed-change gear in the flux of force.
It is also possible, in an advantageous way in the case of the proposed arrangement for carrying out the process according to the invention, to take into account friction value fluctuations occurring to varying degrees during a shift.
In the case of the proposed arrangement for carrying out the process according to the invention, an indirect determination of the gearbox input speed is particularly advantageous in those cases in which a hydrodynamic torque converter is connected ahead of the speed-change gear in the flux of force. This is so since the accessibility of the turbine wheel or of the turbine wheel shaft, often forming the gearbox input shaft itself, or the arrangement of speed sensors in this gearbox area may be hampered, for example because the three blade wheels work in a closed converter housing.
In the case of a proposed arrangement for carrying out the process according to the invention, an embodiment of the invention has proved advantageous in application to the known control of an internal-combustion engine with an exhaust catalytic converter and with a .lambda. probe positioned both ahead of and after the exhaust catalytic converter.
In the case of a proposed arrangement for carrying out the process according to the invention, an embodiment of the invention proved advantageous in application to the known control of an internal-combustion engine to avoid abnormal combustion, so-called knocking.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.